Apparatus for treating material in a vacuum



Aug. 10 1926.

o. MINTON APPARATUS FOR TREATING MATERIAL IN A VACUUM Original FiledMarch 4. 1920 2 Sheets-Sh eet 1 A T'IORNEY 0. MlNfbN' APPARATUS FORTREATING MATERIAL IN A VACUUM Aug. 10, 1926.

Original Filed March 4. 1920 2 Sheets-Sheet 2 a I IVVENTOR ATTORNEYPatented Au 10,-1-926.

UNITED STATES oemm nm'ron, or GBEE'NWICH, connnc'rrcu'r.

PATENT OFFICE.

ori inal application med ma 4', 1920, Serial 1! 20, 1922, Serial m1.54.5;219.

applicationis-a division of my co pending application Treatment ofmaterial in a vacuum and apparatus.filed March 4 1920, Seri No. 363,351,my Case G.

o. seam. Divided and um application m ma Renewed February 17, 1926.

any now known on the market; My invention further. relates to the method(if coating or impregnating sheet material which in- .sures that therewill be no blemishes, un-.

The presentinvention relates to an appaeven surfaces, blisters or'minuteraised porratus and method for the drying of paper and other material,in a vacuum chamber, and then immediately, while still in the vacuumchamber, coating, or coloring, of sizing or impregnating the paper orother material,- and then immediately drying the coated, colored, sizedor impregnated 'paper. or other material while still in the vacuum'chamber.

My improved method consists in passing the material which is to be driedinto a vacuum chamber through a liquid sealing medium which has noaiiinity for the material, subjecting'it to heat to drive off itscontained moisture, immediately coating or coloring, or sizing orimp'regnatin the materi-al while in the vacuum cham er, then subjectingthe coated or colored,,or sized or impregnated materialt'o heat to driveoff its I the occluded air with a coatin A nating compound, and thendrymg'said coatcontained moisture or other liquid, and then passing thematerial out through a seal.-

. This method may be practiced by'the use of various forms of apparatus,some of which are herein disclosed. In any form, however it is essentialthat the apparatus be provide 'with,a closed chamber in which a partialvacuum may be maintained. 7 In or: der that the material to be dried,treated, and again dried may be continuously'p'assed through the vacuumchamber, the latter is provided with "openings closed to the admission.of air by a liquid sealingmedium which has no afiinity for the material.The liquid seal efiectively closes the'entrance and exit passages a aiISt-the admission of air to the chamber, at permits, the passage of thematerial into and out of the chamber. Any other sealing means maybe-used.

My invention further relates to withdraw-- ing' from' the {sheetmaterial substantially.

all, or. a large portion, of its occluded air and fillng the intersticesnormally filled by orimp'reged or impregnated sheet material in thevacuum chamber before subjecting 1 the said sheet material toatmospheric conditions.

My. invention further relates to obtaining a better and more uniformproduct than of the chamber tions due'to the air whichv may be held oroccluded within the sheet material which, in the present practice of.coating asfor ex: ample with a waterproof compound, leadsto'rejectionsor discards due to these imperfections with the consequentwaste of material and' labor.

My invention further ment of paper either from the ,wetend of .a papermachine or from a roll or reel of wet or damp paper, feeding @the web ofwet or damp paper into a vacuum chamber with out breaking the vacuum,drying said web in the vacuum chamber and removing substantially all ofits occluded air, and immediately 'coatmg or impregnating or coloring orsi z-; ingsaid dry web with a coating or impreg-' -nat1ng or coloring orsizing compoundfand.--

then again drying the web, the secondtime or sized compound, W-ltlllllthe vacuum and. rior to sub'ecting the coate or impregnialte compoun tothe action of the atmosere- My invention furtherrelates tomanufacenedand'the size in the paper .is not injured or damaged due todrying at high tempera- My invention furtherrelates to manufacturingcolored papi err .substant'iallyimpa' ing the coloring atter andmordants used in the paper. inon'g chamber and all these steps beincontinuous turing paper wherein the fibers arenotweake and drying itwithout with its coating or impregnating or coloring relates to thetreatother advantages thisinsures that the paper will have brightcolors, which will be substantially uniform in difierent runs of paper,

permitting matching of colored paper withoult. any appreciabledifference in tone or co or.

and expeditiously coating or'impregna'ting sheet material in acontinuous web or sheet. My invention further relates to sizing paper ina vacuum chamber and drying-the sized paper in said vacuum chamber atsiuch low temperatures asnot to iniure the fibers My invention furtherrelates to rapidly .of the aper or the size. 5 My invention furi ther reates to withdrawing the occludedair from the paper and immediatelydrying and then filling the interstices normally filled with theoccluded air with the size, and then drying the thoroughly sized paperin the vacuum chamber before it is subjected to atmospheric conditions.My invention further relates to carrying out this method continuouslywith a continuous Web of paper "which passes into and out of the vacuumchamber Without breaking the vacuum.

More particularly my invention relates to passing material into a vacuumchamber,

without breaking the vacuum, drying it in a heated bath, thenimmediately coating, color ing, sizing or impregnating. the materialwhile still inthe vacuum chamber, then immediately drying the coated,colored, sized or impregnated material while still in the vacuumchamber, and then passing the dry coated, impregnated, sized or coloredmaterial out of the vacuum chamber without breaking the vacuum.

7 My invention further relates to certain steps, and combinations ofsteps, also to certain elements and combinations of elements,

Fig. 2 is a vertical diagrammatic section.

of a modified form of apparatus in which a combination of heated drumsand a heated bath are used to dry and finish the ,material; I Fig. 3 isa vertical diagrammatic section of another modification in whichdifferent sized drums are used with a heated liquid bath to vary thefinish given to' the material. In describing my. invention I willdescribe it as applied to material in the form of .paper though it is tobe distinctly under-- stood that textile fabrics may also be treated bymyprocess and. that my broader claims cover all forms of materials.

In the ordinary drying of a web of paper such high heat is used as toinjuriously affeet the fibers of the paper; and in case the paper iscolored it will materially aflect the coloring matter and mordants used.Drying paper in the high temperatures used in ordinary. practice oftenaffects the size so that the resulting paper varies in quality, is notuniform and is not a perfect product In coating or impregnating-fabricsit is found in practice that the coated fabric will frequently haveblemishes due to large or small blisters and blow holes, these oftenbeing about the size of a pin-head or a pinpoint. This is caused by theair whichis held or occluded being collected, more or less, in smallpockets under the coating or impregnating material, or in some casescausing minute blow holes. In waterproof fabrics thisresults in largequantities of the material being rejected with the consequent loss tothe manufacturer.

By my invention I insure tha'tsubstantially all the occluded air iswithdrawn from the sheet material which will permit the coating orimpregnating material, whatever it may be, to thoroughly filltheseminute inter'stices or pockets normally occupied by occluded air,forming thereby a' better and more uniform product and one devoid ofblisters, blow holes or such. blemishes. By my invention I immediatelydry such coated the vacuum chamber so that when the sheet materialemerges from the vacuum chamber the coating or impregnating material isdry and set without any danger of atmospheric pressure or atmosphericconditions spoiling or marring the finished product.

As previously stated I willdescribe my invention with relation tocoating or impregnating paper, though it is to be understood thattextile fabrics may be treated in the same manner.

V The web of paper 1 is fed direct from the wet end of a paper makingmachine, or in some cases it may be fed from a roll or reel 2 of wet ordamp paper. The Web is fed into the vacuum chamber .A by passing overthe guide roller 4,-into the liquid seal 5-, under the submerging roller6, and thence'in contact with the guide roller 7. This liquid seal 5 maybe of any suitable material which has vor impregnated sheet materialwhile'still in no afiinity for the sheet material treated and has nodeleterious effect upon it. Prefer: ably I use mercury as the sealingmedium 5, but it is to be distinctly understood that any amalgam, alley,or any other suitable liquid sealing medium may be employed which hasthe characteristics above specified. The webl is immediately upon itsentry into the vacuum chamber driedprepara tory to coating or coloring,or sizing. or impregnating it. I have shown in Fig. 1 the material inthe form of a web of paper 1, passing through the heated bath 8,underthe submerging rolls 9, 9 and overthe guide rolls 10, '10.

Preferably this bath 8 is a heated metal" bath, such as mercury, whichmay beheated in any suitable manner, as by the steam pipes 11, 11. It isto be distinctly understood, however, that this heated bath maybe ofany'material which has no afiinity for or 'delfl etcrious-elfect uponthematerial treated. It

. its occluded air will be withdrawn. Then,

while still in the vacuum chamber A, .itis fed through the sizing,coloring, coating, or impregnating bath 13," in the chamber 14, underthe submerging roll and throu' h the squeeze rolls 16, 16 which removeall t e I the pipe 29.-

surplus material of the bath 13.

The material is then fed over the guide roll 17 and immediately driedwhile still in. the vacuum chamber A. I have shown a heated bath 18which has the same characteristics as the bath 8. The coated,impregnated, sized or colored material is fed through the bath 18 underthe submerging rolls 19 and over the guide rolls 20. Bythe time thematerial treated reaches the guide roll 21 it will befdry. It is thenpassed through the exit seal 5 under the submerging roll 22 and out overthe -gu1de roll 23.

The sheet -materia 1 may then be cut, stacked or .rolled in 0 a roll offinished material 24. I

The bath 18, may be heated.in any suitable manner as by the steam pipes11. The coated, sized, impregnating or coloring bath 13' may be heatedby the steam pipes 25. The

liquid' forming the'bath 13 maybe fed into.

the chamber 14 throu the pipe 26,- controlled by the valve 2%. Thischamber 14 can be drained by the pipe 28, controlled by I provide thevacuum chamber A with one or more pipes 30, 3?) connected to anysuitable vacuum apparatus (not shown). I also provide the vacuum chamberwith windows 31, 31 so that the operator can at all times observe thematerial as it passes gontiqnuously through the vacuum cham- If thecoating or impregnating material 9 is a compound including highlyvolatile liquids, these. volatile liquids will of course boil or begiven off ata lower temperature than that given above.

In my-invention I thoroughly dry the coated or impregnated web at arelatively low temperature in the vacuum chamber so as not to injure itsconstituent fibers or ele ments, and also to permit the coating orimpregnating compound to thoroughly set before the web is passed out ofthe vacuum chamber and subjected to atmospheric conditions. In myinvention asmooth and fine product is obtained without-blemishes,blisters or defects due to small portions of air being held under any ofthe coating or seeking to escape therefrom, causing pinholes to appearon the surface. V

In some cases it may be desirable to give the coated, sized, colored, orimpregnated nets of combustion material 1 'a difierent finish from 'whatwould receive in the apparatus just described and illustrated in Fig; v

I may for example pass thd web 1, Fig. 2, into the vacuum chamber Athrough a similar liquid seal 5 and over comparatlvely smallguiderollers 32, 32 and in contact with relatively large submerging rollers.33, 33

which may be heated and rotated, or not,

as found convenient or desirable. These rollers 33, 33 are mounted inthe liquid bath 34 preferably of mercury, though of any suitablemediumhaving thecharacter-- I istics previously described in connection withthe baths 8 and 18, Eig. 1. The liquid in this bath may be heated in anysuitable manner as by steam, hot Water or prodpassing through thechamber 35.

v After the web 1 has been thoroughly dried by its passage through thisbath 34 and in contact with the drums 33, 33 and the guide rollers 32,32 it is immediately, while still in .the vacuum chamber, passed intothe compartments .36, containing the coating or impregnating liquid 13,under the roll 11, thence through the squeeze rollers 16, 16 over theguide roller '37. and through the second liquid bath 38, while incontact with the drums 0r cylinders 39, 39; the web passing overtheguide rollers 40, 40. The liquid bath 38 is preferably mercury, butit may be of any suitable material having the characteristics previouslydescribed. This second bath may be heated in any suitable manner, as bysteam, hot water, or products of combustion assing through the chamber41. .The coated or impregnated or sized or colored Web is dried in thesecond bath 38, where the coating or impregnating or coloring or sizingmaterial is thorough 1y set 'in' the web at relatively low temperatureswhich temperatures do not injure the constituent elements or fibers ofthe web. i

It is then passed out of the vacuum machine through the second liquidseal 5 under the submerging roller 22 and over they uide roller 23 whereit may be immediatey wound into a finished roll of coated or impregnatedpaper or. fabric 24.

The finish of the web, particularly if it is of paper, may be stillfurther varied by changing the size of the'drums or cylinders 32, 33 and39 and 40. These changes may be mad within wide limits. Simply forpurpose& of illustration Ihave shown another variation of my invention,Fig. 3,'in which the vacuum chamber A is rovided with the same liquidbaths 34 an '38. The guide rollers 43-, 430i the first li uid bath andthe'guide rollers-44, 44;;of t e second liquid bath arefsubstantiallythe same size as the similar guide-rollers 32 and 40 of Fig. 2, but thedrums or cylinders 45, 45 of the first liquid. bath and the drums 46,546of the second liquid bath are smaller. thanthe correspondin drums 33, ?3.and 39, 39, respectively, 0 Fig. 2. In this modification the web 1 willnot have a finish quite so fiat and smooth as given by the apparatusshown in Fig. 2, but will give a flatter and smoother finish than L tus.of Fig. 1. While these different forms are shown, it is of course to beunderstood that they are simply illustrative and that my invention isnot to be confined to them.

The finish given to the material treated will also depend somewhat onthe depth to which the web 1 is caused to penetrate the heated liquidbaths 8,18 and 3a, 38. The deeper it is forced into the bath-the greaterwill} be the pressure of the liquid upon the We The thermal efiiciencyof my. vacuum method is very much greater than that of the atmosphericcylinder drying heretofore 1n unlversal-us for drying paper.Theoretically, it requires'about 5287 pounds of steam to dry one ton ofpaper at atmospheric pressure, but to compensate for convection andconduction losses, and those due to leaks in the piping system, andother inefiiciencics, it has been shown in practice that about I 10,600pounds are required.

In my method, usingv a vacuum of about 28", the convection, conductionand piping losses are exceedingly small and the total steam required todry a ton of paper by my method is approximately 5200 pounds.

It is an established fact that paper dried at lowtemperatures is muchstronger than when .it is dried at the high temperatures used in papermachine atmospheric drying. Paper dried in a vacuum of '28", or at atemperature of about 100? F., as in my method, is very muchstronger thanpaper dried at atmospheric pressure, when the steam in the driers is at228 F. When in the web as it passes over the cylinder.

Furthermore, in m method there is a great saving of heat (Zrsteam)because the process is carried on in a vacuum chamber which acts on theprinciple of athermos bottle, and the steam and vapors driven out of thewet paper are caught in the closed vacuum chamber, and conducted away tothe -condenser. The operating room is free from steam, humidity andheat, and fans, and exhausters are dispensed with. In the gis JD. by theappara-.

desired, said bath having use of my method the apparatus is at all timesoperating under definite humidity, the control of the drying can beclosely standardized, and the moisture content in the paper carefullyregulated.

Having pointed out the many advantages of my method and'a paratusoverthose heretofore used, it will e apparent that the use of myinvention results in great economy in the initial cost of apparatus andin large savings in cost of. operation, maintenance and repairs.

Having. thus described this invention in connection with illustrativeembodiments thereof, to the details of which I do not de sire to belimited, what is claimed as new and what is desired -to secure byLetters Patent is set forth in the appended claims,

What I claim is 1.' An apparatus for treating material including avacuum chamber, means to permit the material to pass into and out ofsaid vacuum chamber without breaking a2? vacuum, drying means includingahe (1 bath and means mounted in the bath to exert a predetermineddegree of tension on the fibers of the wet material to give theparticular finish, smoothness or flatness desired, coating orimpregnating means mounted in the vacuum chamber, and second dryingmeans including a heated bath and means mounted in the bath to exert apredetermined degree. of tension upon the fibers of the coated orimpregnated material to give the particular finish, smoothness orflatness desired, said bathhaving no aflinity for or deleterious effectupon said material, and

means to permit the dry coated orkimpregnated materialv to pass from"the vacuum chamber without breaking the vacuum.

2. An apparatus for treating paper including a vacuum chamber, means topermit the paper to pass into and out of said vacuum chamber. withoutbreaking the vacuum, drying means including a heated bath and meansmounted in thebath to exert a predetermined degree of tension on thefibers of the wet material to give the articular finish smoothness orflatness desired,

coating or impregnating means mounted in the coated or impregnatedpaperto' give the particular finish, smoothness'or flatness no aifinityfor or deleterious efl'ect upon sand paper, and means to permit the drycoated or lmpregnat'ed pagpr to pass from the vacuum chamber wit outbreaking the vacuum. I 3. An apparatus for treating material including avacuum chamber, means to permit the material to pass into and out ofsaidvacuum chamber without breaking 1 the vacuum, drying means including aheated bath and means mounted in the bath to exert a predetermineddegree of tension on the fibers of the wet material to give theparticular finish smoothness or flatness desired, coating or Jimpregnating means mounted in the vacuum chamber, and second dr ingmeans including a heatedbath and r01 s of the required diameter mountedin 10 the bath to exert a predetermined degree of tension upon thefibers of the coated crimpregnated material to give the particularfinish, smoothness or flatness desired, said bath having no affinity foror deleterious effect upon said material, and means to permit the drycoated or impregnated material to pass from the vacuum chamber withoutbreaking the vacuum.

' OGDEN MINTONa

